In the annals of murder trials, few testimonies can rival the impact of slain teenager Trayvon Martin's mother Sybrina Fulton: "I heard my son screaming."

She was referring to the voice on an audio recording of a 911 call that has been at the center of the prosecution's case against George Zimmerman, accused of fatally shooting Martin during a scuffle.

That is, until late Friday when the defense called Zimmerman's mother, Gladys, to the stand. She, too, identified the same recorded voice as her son's. She was certain, she said, "because he's my son."

Suddenly, this high-stakes trial has become a test of the credibility of two mothers.

If the voice heard screaming in the background of the recording belonged to the dead teen, as the prosecution claims, then it is less easy to believe that Zimmerman was acting in self-defense, as he claims.

If the voice belongs to Zimmerman, then one might conclude that he felt sufficiently threatened to squeeze the trigger. Zimmerman, 29, was acting as a volunteer neighborhood watchman the night he shot Martin, 17, whom he has described as acting suspiciously.

Into the mix enters a ghost witness that is both more amorphous and exponentially more powerful than any other: Maternal Instinct. Clearly, attorneys for both sides are plowing this fertile field, counting on the maternal synchrony of the six jurors --- all of whom are women, five of them mothers.

One of the mothers testifying is obviously wrong and jurors will have to rely largely on their own instincts to determine who is right. The judge has ruled against allowing voice experts to testify.

Their answer likely will be the most probative piece of evidence in the trial despite the fact that there can be no certainty. The truth, to the extent it can be surmised, may well hinge on an assumption that is interesting to consider. It isn't so much a gut feeling but is primal, deep-brain and fiercer than mere logic.

Does maternal instinct convince these mothers that they are right? Or does maternal instinct compel each to protect her son regardless of what may be true?

Second-guessers have an array of questions to entertain: Would a mother lie about such a thing? Could she? Would she wish another man convicted on the basis of her sense of things? Can she know with certainty that the voice in the background, barely audible, is that of her son and not of the other man?

The last question is most compelling. Can she?

Most mothers know the sound of their own child's cry from the moment of birth. From personal experience, I can vouch for the strange ability to discern one's own from all others. If my baby was crying in the hospital nursery, I was halfway down the hall to retrieve him before I realized I'd left the bed.

Does this sort of attunement last through time? Logic suggests that as a child's dependency decreases, so does the acuteness of a mother's instinctive responses. But experience tells us that the mother-child bond does not diminish with time. Every dead soldier is still his mother's baby.

Would a mother recognize her son's cry for help on a recording? It is possible to believe so, while also possible not to believe so. Recordings often distort voices; other noises interfere. Further complicating are the unconscious desires or needs of the listener. A mother needs to believe that whatever harm came to her son was not his fault.

In fact, it was when defense attorney Mark O'Mara suggested that Fulton might have hoped to hear her son's voice that she uttered those five words and said, "I didn't hope for anything. I just simply listened to the tape."

Trayvon Martin was undoubtedly a beloved son who didn't deserve to die. He was unarmed, on his way home from a convenience store. Did he attack George Zimmerman? Was Zimmerman, also a beloved son, so mortally afraid that he had no choice but to shoot Martin in the heart?

No one envies the terrible decision these jurors must make. Matters were made worse Friday when medical examiner Shiping Bao testified that Martin likely lived another one to 10 minutes and opined that he suffered and was in pain.

Maternal instinct may not be a reliable witness, but in the absence of verifiable truth, she/it may prove to be the bullet through the heart of this case.

Oh really! So if someone chases you, catches up to you, draws a gun and moves near enough for you to grab the gun, you would just stand there. You do not believe that Trayvon Martin had the right to defend himself by grabbing the gun and yelling for help while he proceeded to push forward, knocking Zimmerman down while continuing to yell for help and trying to get the gun out of Zimmerman's hand. I also note that you are assuming Zimmerman's account is accurate while experts have testified that the injury on Zimmerman's head only indicates a single knock against the ground, consistent with my possible scenario above. Also, witnesses are inconsistent as to whop was on top. Fact remains, Zimmerman was the aggressor. He was the one ordered by police to not go after Trayvon Martin and elected to do so anyway. He is the one that chose the course of action based on his unreasonable profiling. He had no authority to stop Trayvon Martin, thus was in violation of Trayvon Martin's civil rights to attempt to stop him. He's "suspicions" are not sufficient cause. From the uncontested facts, it is obvious that Zimmerman is guilty, the only question is degree: first degree murder, second degree murder, voluntary manslaughter or involuntary manslaughter. Unfortunately, because of his father's influence, he might get away without jail time; however, he will probably be facing a wrongful death lawsuit which is much easier to prove.

The neighborhood in which Zimmerman lived had seen a recent spate of break-ins. Zimmerman, in his duties as "neighborhood watch" (we can discuss the validity of his position or the apparent enthusiasm he displayed later) noticed a young man walking around the neighborhood when it was raining. The young man displayed enough odd behavior to make Zimmerman question whether he was high (guess what? according to the medical examiner, there was marijuana in Martin's system). Zimmerman called the police non-emergency line. He spoke to the operator for about 4 minutes. He described Martin's actions. The operator then asked for Martin's race, which Zimmerman said "He looks black." No matter how much NBC tried to make Zimmerman the racist, there is no racist connotation to that statement.

Two minutes into the conversation, Martin takes off running. At the time, Martin was about 500-1000 feet from his townhouse. Zimmerman was more than double that distance, and around a corner or two from the townhouse. Also, Zimmerman was 10-15 years older and 50 pounds heavier than Martin. Do you really think Martin couldn't make it to his townhouse before Zimmerman, even though Martin started running two minutes before Zimmerman even got off the phone with the police?

You throw out a scenario, allow me to rpely in kind:
George Zimmerman saw Martin walking around and got suspicious. Martin noticed Zimmerman following him from a distance. We know this, because he called Zimmerman a "creepy @$$ cracker." Martin runs off and hides, finding a vantage point to scope out his follower. Once he sees Zimmerman hang up with the police, Martin steps out of the shadows and confronts Zimmerman, who is shorter and heavier and older. Martin initiates the confrontation and shoves Zimmerman to the ground. Eyewitnesses say that Martin was hitting Zimmerman "MMA style." Martin and Zimmerman simultaneously go for Zimmerman's pistol, but Zimmerman is able to get the gun and fires off a single shot at point blank range while fighting.

It's just a scenario, but it's also just as likely as the one you proposed.

Here too, you are relying on Zimmerman's description of events. We only have Zimmerman's account that says Martin ran and the distances involved. As to your statement about the eyewitnesses, the testimony to which I listened had inconsistent accounts, some indicating they say George on top doing the hitting. Assuming for a moment that your scenario is at all accurate, put yourself in the shoes of Mr. Martin. You see a man watching you. You are aware of break-ins in the area and have never seen George or his vehicle in the area. Then you think, "That guy saw me and doesn't want a witness to his crimes" - so you run only to be chased confirming your fears of someone up to no good. You don't want to lead him to where you live, he might ambush you later so confrontation might be better. Then you see the gun and fear for your life and take the steps you think give you the best chance for survival. Still remains that George is the aggressor because he initiated the chase and Trayvon only reacted in self defense.

PS, for the blind denier, You are reading things that I didn't say - no reference to race. You are the one that wants to play the race card for Georges defense. Why do you think it was okay for Zimmerman to murder anyone?

My understanding is that Zimmerman was pretty well known around the area. His was probably a bit over-zealous in his role as "Neighborhood Watchman," but he was by no means a stranger.

The media has portrayed Trayvon Martin as a sweet innocent 12-year-old (at least in pictures) and in some cases has gone out of their way to hide the pictures of Martin blowing pot smoke, or flashing gang signs, or talking about fights. It may very well be that Martin was doing nothing wrong on the night in question, and that a neighborhood watchman was heightened paranoia based on recent break-ins overreacted in watching him and following him. But the fact remains that Martin had a two-plus minute lead on Zimmerman to cover no more than a thousand feet. That's more than reasonable for an athletic 17-year-old to cover. Yet, somehow Martin found himself in confrontation with Zimmerman. To me, the only way that confrontation happens is if Martin turned back and instigated the conversation.

And you can't just dismiss Zimmerman's account, though you shouldn't take it as gospel either. Seeing the evidence and hearing his testimony of the actions, I feel more compelled to take Zimmerman's side. The Prosectuion has done itself no favors in this case by the witnesses they've called. Rachel "I don't read cursive, 'creepy @$$ cracka' ain't racist" Jeantel did more damage to the prosecution's case than the aforementioned Trayvon Martin pictures likely would've done.

"Why do you think it was okay for Zimmerman to murder anyone?"
By that statement, you make the claim that Zimmerman planned, with malice aforethought, to take Trayvon Martin's life that night. By that statement, you make it sounds as though killing someone in self-defense should be classified as murder. Do you really think that?

Zimmerman did plan to be a neighborhood watcher. He did plan to bring a gun, he did decide to load that gun with lethal bullets. He chose to chase someone calmly walking through the neighborhood, minding their own business while talking on a cell phone. All these actions add up to planning to put himself in a potential situation to kill someone. He know he wanted to be a policeman and wanted to prove himself to police friends. He was hunting for a situation that could aid in that endeavor and not thinking rationally. But he did not plead not guilty by reason of insanity. You have made a reasonable argument voluntary manslaughter, but he is still guilty of the original assault. Assume a situation where two people are involved in a fight where number one chased down number 2, a fight ensues and number 2 ends up dead, then this is a crime regardless weapons involved. The only question would be if number one had lethal intent, making it murder, or the death were an accidental consequence of his initial action, making it manslaughter. A drunk driver that hits and kills someone accidentally is guilty of manslaughter because he chose to put himself in a potential situation that increased his chances of the accident.

PS Blind denier, Would you have the same opinion if Zimmerman were black and Martin was white?

You're still assuming that Zimmerman somehow chased down the far more athletic Martin who had a two-plus minute lead on him. Also, you say that Martin was calmly minding his own business. If that's so, then why call the cops? If Zimmerman is as zealous as you claim him to be, then he would also, reasonably, be looking for actual crime or those with the potential for crime. He stated to the cops that Martin looked like he was up to no good. Someone calmly minding their own business doesn't look like they're up to no good.

The forensic team has stated that the muzzle of Zimmerman's gun was against Martin's clothes, but it was not against his skin. If Zimmerman was on top, as you say some of the eyewitnesses state, then it is an impossible situation, unless you think Zimmerman lifted Martin's shirt, and then shot him. However, if Martin is on top and leaning forward, like one would when punching someone, then the situation becomes incredibly likely.

Also, if Zimmerman were black and Martin white, it's unlikely you'd have ever heard of this case. See, the media hasn't exactly treated black-on-white crime the way it has treated this.

And Zimmerman isn't white. His father is. His mother is Peruvian, so he is mixed race, though he identifies as Hispanic. The medias has tried like crazy to identify him as white, going so far as to say he is a "white Hispanic." Applying that same logic to our current President, is Barack Obama black or white? His mother is white. His father is black. By the media's "Zimmerman Logic," Obama is a "white African American." How silly is that?

It's amazing to me that the race pimps and their liberal media enablers have stage managed this cut and dried self defense shooting into a white versus black and liberal versus conservative 'crisis'. ...................................... George Zimmerman is hispanic. I will admit that he does not have a spanish accent so maybe this is enough in some closed minds to make him 'white' but none the less, where does the white versus black conflict come from ? ...................................... ...................... As for liberals versus conservatives, any time a person uses their Constitutionally guaranteed right to armed self defense they just can't stand it. ..........................If one pays even the slightest attention to the news coming out of the trial it has to be obvious that the prosecution has NO case. This is a politically created dog and pony show. Does ANYONE think this is a good thing ?